What is the Largest Giant Butterfly?

We measure butterfly size by approximate wing-span.

Butterflies can range in size from as small as a dime (less than 1 inch) to about 9.5 inches in wingspan.

One of the questions I get most often is "What is the largest butterfly?"

For the answer, we need some qualifiers...

Biggest Butterflies in the World

In the world, one of the largest butterflies is the Cairns Birdwing (Ornithoptera euphorion). These butterflies are native to Australia, so unless you garden down under, you are not likely to have one visit your butterfly habitat. However, since they are so amazing, many exotic butterfly houses have them on display. Luckily, you can visit a butterfly house in the states and possibly see birdwings on display.

Below is a photo of my hand next to a female Cairns Birdwing butterfly, the biggest butterfly in the world! Notice her body is about the size of my pinky.

This interesting and mega-sized flier is also sexually dimorphic. That means that the males and females look very different, the males are typically more showy. Many people understand this concept because they have seen sexual dimorphism in birds like peacocks, cardinals and buntings.

Generally speaking, female butterflies are larger than males. Female Cairns butterfly wings can be over 9 inches in span!

Both of these characteristics can be found in this species. With Cairns Birdwings, the boys are prettier but the girls are bigger...hmm how strange! That is usually opposite of what we humans think of.

The photo below is a male Cairns Birdwing.

Male Cairns Birdwing is bright and beautiful like a stained glass window

Biggest Butterflies in the US

Of all the families of butterflies in the United States, Papilionidae has the largest members. We commonly call these Swallowtails.

There are many big swallowtails in many states. Some are sexually dimorphic and some are not. But in all cases, the gals are larger than the guys.

Just like people, butterflies vary in size. But, for the most part, the biggest butterfly in the US is the female Giant Swallowtail (Papilio cresphontes). Her wingspan can be around 6 inches.

Giant Swallowtail larvae look like bird droppings, but the adult butterfly is large and stunning!

Biggest Butterflies in Florida

Florida has plenty of swallowtails including the Tiger, Spicebush, Pipevine, Eastern Black, Gold Rim, Zebra, and more. Happily, Giant Swallowtails are quite common.

One reason they are so plentiful is that they host on citrus trees. Since we have lots of orange groves, lime trees, grapefruits and other citrus in the Sunshine State, Giant Swallowtails are everywhere.

Giant Swallowtails are the largest butterflies in the US

In my backyard butterfly habitat, Giant Swallowtails are attracted to Wild Lime. This is their very prickly host plant. It is a native tree and it doesn't make any edible fruits. Honestly, it's not the most lovely tree, but because I want Giant Swallowtails, I tolerate it.

If you would like to use a different kind of citrus, that would work too. However, there may be a conflict of interests because the larvae will be eating the leaves and that could compromise the fruit harvest. For years I hosted them on key lime trees.

You can tell when a female Giant Swallowtail butterfly is laying eggs because she hovers over the plant and curls her abdomen under as she deposits it as seen in the video below.

You won't miss these butterflies because they are so graceful and giant!

Butterflies of all sizes are amazing, but if you want to regularly see your local Giant or other Swallowtails, plant their host plants and enjoy the show.

For other swallowtails that live in the US check out my book, Butterflies of the Southeast.

Go Big or Go Home

Jessica